Difference b/w Emulator and Simulator?

Simulator -

write a program that draw the calculator's display and keys and when
user clicks on the keys your progra, does what the old calculator did.

duplicate the behaiour of device

Emulator -

you get a dump of the calculator firmware , then write a program
that loads the firmware and interpret in the sameway the u.p in the
calculator did.

duplicate the inner working of the device.

in emulator s/w platform is created on which the emulated code can be run
in ahost computer having different h/w and a different instr set.